title: Damage-induced DNA replication stalling relies on MAPK-activated protein kinase 2 activity.
abstract: DNA damage can obstruct replication forks, resulting in replicative stress. By siRNA screening, we identified kinases involved in the accumulation of phosphohistone 2AX (γH2AX) upon UV irradiation-induced replication stress. Surprisingly, the strongest reduction of phosphohistone 2AX followed knockdown of the MAP kinase-activated protein kinase 2 (MK2), a kinase currently implicated in p38 stress signaling and G2 arrest. Depletion or inhibition of MK2 also protected cells from DNA damage-induced cell death, and mice deficient for MK2 displayed decreased apoptosis in the skin upon UV irradiation. Moreover, MK2 activity was required for damage response, accumulation of ssDNA, and decreased survival when cells were treated with the nucleoside analogue gemcitabine or when the checkpoint kinase Chk1 was antagonized. By using DNA fiber assays, we found that MK2 inhibition or knockdown rescued DNA replication impaired by gemcitabine or by Chk1 inhibition. This rescue strictly depended on translesion DNA polymerases. In conclusion, instead of being an unavoidable consequence of DNA damage, alterations of replication speed and origin firing depend on MK2-mediated signaling.
authors.affiliation: Institute of Molecular Oncology and Göttingen Centre of Molecular Biosciences, Faculty of Medicine, University of Göttingen, 37077 Göttingen, Germany.
authors.forename: Frederik
authors.initials: F
authors.lastname: Köpper
authors.forename: Cathrin
authors.initials: C
authors.lastname: Bierwirth
authors.forename: Margarete
authors.initials: M
authors.lastname: Schön
authors.forename: Meike
authors.initials: M
authors.lastname: Kunze
authors.forename: Ingegerd
authors.initials: I
authors.lastname: Elvers
authors.forename: Dominique
authors.initials: D
authors.lastname: Kranz
authors.forename: Priyanka
authors.initials: P
authors.lastname: Saini
authors.forename: Manoj B
authors.initials: MB
authors.lastname: Menon
authors.forename: David
authors.initials: D
authors.lastname: Walter
authors.forename: Claus Storgaard
authors.initials: CS
authors.lastname: Sørensen
authors.forename: Matthias
authors.initials: M
authors.lastname: Gaestel
authors.forename: Thomas
authors.initials: T
authors.lastname: Helleday
authors.forename: Michael P
authors.initials: MP
authors.lastname: Schön
authors.forename: Matthias
authors.initials: M
authors.lastname: Dobbelstein
mesh_terms: D000818:Animals; D000964:Antimetabolites, Antineoplastic / Q000494:pharmacology; D045744:Cell Line, Tumor; D000071877:Checkpoint Kinase 1; D004249:DNA Damage; D004261:DNA Replication; D004277:DNA, Single-Stranded / Q000235:genetics / Q000378:metabolism; D003841:Deoxycytidine / Q000031:analogs & derivatives / Q000494:pharmacology; D059565:G2 Phase Cell Cycle Checkpoints; D055785:Gene Knockdown Techniques; D006657:Histones / Q000235:genetics / Q000378:metabolism; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism*; D020935:MAP Kinase Signaling System; D051379:Mice; D018345:Mice, Knockout; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D014466:Ultraviolet Rays; D048051:p38 Mitogen-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism; D000093542:Gemcitabine; D000099190:MAP-Kinase-Activated Kinase 2
chemical_list: D000964:Antimetabolites, Antineoplastic; D000071877:Checkpoint Kinase 1; D004277:DNA, Single-Stranded; D003841:Deoxycytidine; D006657:Histones; D047908:Intracellular Signaling Peptides and Proteins; D011494:Protein Kinases; D017346:Protein Serine-Threonine Kinases; D048051:p38 Mitogen-Activated Protein Kinases; D000093542:Gemcitabine; D000099190:MAP-Kinase-Activated Kinase 2; C468783:H2AX protein, human; C475961:gamma-H2AX protein, mouse; C000605867:CHEK1 protein, human; C000605869:Chek1 protein, mouse